It is known to dispose a layer of polychloroprene glue between the metal end fitting and the last fin. This layer of glue provides sealing between the end fitting and the fin.
German patent publication DE-A-2,855,211 describes a seal made of silicone grease.
However, it is observed with both these arrangements that the seal deteriorates progressively over time: further, in particular due to traction forces, the seal may be partially damaged.